The invention relates to a covering made of elements that can be mechanically interconnected and to a method for producing elements.
Wall, ceiling and floor coverings, such as prefinished parquet, hardwood floors or laminate floors are constructed from several rows of panels having a largely rectangular configuration. Conventional panels have on one longitudinal side and one head face continuous grooves, and on the corresponding opposite longitudinal side or head face continuous springs which formfittingly match the grooves. The panels of two adjacent rows are arranged with a mutual offset and are installed by joining groove and spring.
It is known to provide on the grooves and springs mechanical locking means which lockingly engage in adjacent panels of the floor covering. This arrangement is intended to prevent gaps from forming in the installed floor covering due to expansion or contraction processes. Matching locking elements are formed on the groove and spring of the panels as indentations, recesses or protrusions, so as to hold connected panels in the joined position without an adhesive. Typically, the panels are rotated or latched into each other along their longitudinal sides and subsequently displaced laterally, so that the locking rails engage at the head faces. To facilitate this, gentle hammer strokes can be applied from the opposite head face by using a tamping block. There is, however, the risk that the panels can be damaged even when taking the greatest care.
Solutions are also known where in the abutting head faces need not be locked by hammer strokes, but instead by displaceable spring elements. One example is the floor covering described in DE 20 2007 018 662 U1, wherein identically constructed panels can be interlocked by a substantially vertical joining motion in the horizontal and vertical direction, whereby locking in the vertical direction is attained with at least one spring element which is movable in the horizontal direction and formed as one-piece from the core on a lateral edge, with the spring element during the joining movement locking behind a locking edge extending substantially in the horizontal direction. The at least one spring element is free with respect to the core in the direction of the top side and in the direction of the opposing side edge and is connected with the core on at least one of the two ends of its side edge. Disadvantageously, for locking the spring element, a horizontal force must first be applied to the spring element so as to push the spring element back before releasing the built-up spring tension, causing the spring element to snap into place behind the locking strip. The floor boards described in EP 1 350 904 A2 are constructed similarly, wherein the spring to be attached on a head face of a floor covering element must first be pushed back before being able to snap in place in a receptacle provided for locking. In each case, a sufficiently large clearance space must be provided behind the spring, so that the spring can be pushed back before locking.